US8971922B2 - Apparatus and method for measuring position of terminal located in indoor using wireless network - Google Patents
Apparatus and method for measuring position of terminal located in indoor using wireless network Download PDFInfo
- Publication number
- US8971922B2 US8971922B2 US13/959,380 US201313959380A US8971922B2 US 8971922 B2 US8971922 B2 US 8971922B2 US 201313959380 A US201313959380 A US 201313959380A US 8971922 B2 US8971922 B2 US 8971922B2
- Authority
- US
- United States
- Prior art keywords
- band
- terminal
- aps
- information
- measurement result
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
- H04W4/02—Services making use of location information
- H04W4/023—Services making use of location information using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds
Definitions
- the present invention relates to positioning, and more particularly, to a method and apparatus for measuring the position of a terminal located in indoor using a wireless network.
- An assisted global positioning system is a satellite-based positioning system that can under certain conditions (mostly, when a data link with a server is established) improve a GPS startup speed and reduce time to first fix (TTTF) (which is a time taken to fix a data link with an artificial satellite).
- An A-GPS is mainly used in a user equipment (UE) (e.g., a cellular phone or a smart phone) having a built-in GPS and was developed by Federal Communications Commission in order to transmit location information during 911 emergency calls.
- UE user equipment
- UE user equipment
- a UE can support location information to a user via A-GPS technologies.
- A-GPS technologies are location information service technologies that are mainly used in 3rd generation partnership project (3GPP) standard and currently provide many services to subscribers.
- 3GPP 3rd generation partnership project
- the UE receives GPS (which corresponds to A-GNSS in terms of 3GPP) satellite information and transmits or receives location related information of a base station (BS) based on the GPS satellite information to receive accurate location information through a server that manages location information of the BS.
- GPS which corresponds to A-GNSS in terms of 3GPP
- BS base station
- A-GPS technologies have been already used to provide more accurate location information using information received by a UE from a GPS via communication with a server that manages location information of a BS. Recently, A-GPS technologies have been mainly used in fields of wideband code division multiple access (WCDMA) of 3GPP standard or code division multiple access (CDMA) of 3GPP2 standard. In areas where UEs cannot easily receive location information, locations are estimated using satellite information alone, which is disadvantageously less accurate than A-GPS technologies. In addition, time required to acquire location information may be changed according to an area.
- WCDMA wideband code division multiple access
- CDMA code division multiple access
- a UE accesses a location information server of a BS using information received from a GPS to obtain a more accurate location, which is called A-GPS technologies.
- A-GPS technologies In general, an error range is reduced within several meters even if accuracy is changed according to a location of a UE within an area managed by a BS.
- the present invention is directed to a method and apparatus for measuring the position of a terminal located in indoor using a wireless network that substantially obviates one or more problems due to limitations and disadvantages of the related art.
- An object of the present invention is to provide a method for measuring the position of a terminal located in indoor using a wireless network.
- Another object of the present invention is to provide a method and apparatus for measuring the position of a terminal located in indoor using a wireless network.
- a method for measuring a position of a terminal located in indoor using a wireless network includes receiving measurement result information obtained by performing measurement with respect to signals from three or more access points (APs), and calculating the position of the terminal using the measurement result information.
- the measurement result information includes signal strengths measured with respect to signals from a first band and a second band of each of the three APs.
- the calculating the position of the terminal may include (a) measuring signals from a first band and a second band of a first AP among the three APs, calculating a distance between the terminal and the first AP per band from the signal strengths per band, and calculating a final distance between the terminal and the first AP using the distances calculated per band; (b) calculating respective final distances between the terminal and the remaining APs except for the first AP among the three APs using the same method as step (a); and (c) calculating the position of the terminal using the respective final distances between the terminal and the three APs calculated in steps (a) and (b) and the positions of the three APs.
- the final distance between the terminal and the first AP measured in step (a) and the final distances between the terminal and the remaining APs except for the first AP measured in step (b) may be calculated by averaging the distances calculated per band.
- the final distance between the terminal and the first AP measured in step (a) and the final distances between the terminal and the remaining APs except for the first AP measured in step (b) may be calculated by applying weight factors to the distances calculated per band. If the weight factors are applied to the distances calculated per band, a larger weighting factor value may be applied to a distance calculated from a band in a line of sight (LOS) environment.
- LOS line of sight
- a larger weighting factor value may be applied to a distance calculated from a band in which at least one of a signal strength received per band and a delay time satisfies a predefined threshold condition (e.g., large signal strength and a short delay time).
- a predefined threshold condition e.g., large signal strength and a short delay time.
- the signal strengths measured with respect to the signals from the first and second bands of each of the three APs included in the measurement result information may be obtained by, at the terminal, accessing the first band, performing measurement, performing band switching, accessing the second band and performing measurement.
- the signal strengths measured with respect to the signals from the first and second bands of each of the three APs included in the measurement result information may be obtained by, at the terminal, simultaneously accessing the first band and the second band and performing measurement.
- the method may further include transmitting information including at least one timing information of a measurement time, a measurement result information transmission time and band switching information to the terminal.
- the band switching information may include information about a band, information about a channel, status information of the channel and channel access time (start or wait) information.
- Band switching may be performed using a point inter frame space (PIFS) of a contention free period (CFP) or a short inter frame space of a contention period (CP) of a superframe.
- PIFS point inter frame space
- CCP contention free period
- CP contention period
- the position of the terminal may be measured at an AP or a location server.
- an apparatus for measuring a position of a terminal located in indoor using a wireless network includes a wireless communication unit for receiving measurement result information obtained by performing measurement with respect to signals from three or more access points (APs), and a position information module for calculating the position of the terminal using the measurement result information.
- the measurement result information includes signal strengths measured with respect to signals from a first band and a second band of each of the three APs.
- the location information module may (a) measure signals from a first band and a second band of a first AP among the three APs, calculate a distance between the terminal and the first AP per band from the signal strength measured per band, and calculate a final distance between the terminal and the first AP using the distances calculated per band, (b) calculate respective final distances between the terminal and the remaining APs except for the first AP among the three APs using the same method as step (a), and (c) calculate the position of the terminal using the respective final distances between the terminal and the three APs calculated in steps (a) and (b) and the positions of the three APs.
- the position information module may calculate the final distance between the terminal and the first AP by averaging the distances calculated per band of the first AP and calculate the final distances between the terminal and the remaining APs except for the first AP among the three APs by averaging the distances calculated per band of the remaining APs.
- the calculated final distance may be obtained using an average of the distances obtained per band or AP, for example.
- the final distance between the terminal and the first AP or the final distances between the terminal and the remaining APs except for the first AP may be calculated by applying weight factors to the distances calculated per band. If the weight factors are applied to the distances calculated per band, a larger weighting factor value may be applied to a distance calculated from a band in a line of sight (LOS) environment. If the weight factors are applied to the distances calculated per band, a larger weighting factor value may be applied to a distance calculated from a band in which at least one of a signal strength received per band and a delay time satisfies a predefined
- the position of the terminal can be more accurately estimated indoors using Wi-Fi using one or more bands, it is possible to increase positioning accuracy.
- FIG. 1 is a schematic block diagram showing the configuration of a user equipment (UE) 100 according to the present invention
- FIG. 2A is a diagram illustrating a triangulation method among several positioning methods and FIG. 2B is a diagram illustrating the concept of time of arrival (TOA);
- FIG. 3 is a diagram illustrating a fingerprinting positioning method in a Wi-Fi positioning system
- FIG. 4 is a diagram showing a beacon frame used in a Wi-Fi system
- FIG. 5 is a diagram illustrating an indoor positioning method according to Embodiment 1 of the present invention.
- FIG. 6 is a diagram illustrating an indoor positioning method according to Embodiment 3 of the present invention.
- FIG. 1 is a schematic block diagram showing the configuration of a user equipment (UE) 100 according to the present invention.
- the UE 100 may include a wireless communication unit 110 , an audio/video (AN) input unit 120 , a user input unit 130 , a sensing unit 140 , an output unit 150 , a memory 160 , an interface unit 170 , a controller 180 , a power supply unit 190 , etc.
- AN audio/video
- AN audio/video
- FIG. 1 is a block diagram showing the configuration of the UE according to the present invention
- the configuration of the UE is equally applicable to a base station (BS), an access point (AP) and a location server.
- BS base station
- AP access point
- location server a location server
- FIG. 2A is a diagram illustrating a triangulation method among several positioning methods.
- At least three reference points are necessary to estimate a real-time position of an object, distances from the at least three reference points are calculated and intersections thereof are detected to perform position estimation, as shown in FIG. 2A .
- the position (xy, yu) of the terminal (or can be referred as mobile terminal, user equipment and like that) may be calculated through a recursive least squares (LS) method using the equations shown in FIG. 2A .
- the distance measurement method used in triangulation may be expressed as follows.
- a distance between two points may be obtained using Friis's formula as follows.
- Signal transmission times between a plurality of APs, the positions of which are known, and a terminal are measured to calculate the position of the terminal and a distance between an AP and a terminal can be calculated through accurate time synchronization therebetween.
- FIG. 2B is a diagram illustrating the concept of time of arrival (TOA).
- a time TOA(tp) required when a signal transmitted from a Node A to a Node B arrives may be expressed by
- T roundA denotes a time required when a packet is transmitted by a transmitter (Node A) to a receiver (Node B) through an arbitrary number of intermediate connections or communication networks and then a response signal thereto arrives at the transmitter (Node A) through the intermediate connections or communication networks.
- FIG. 3 is a diagram illustrating a fingerprinting positioning method in a Wi-Fi positioning system.
- a region in which the position of the terminal will be measured is divided into sub-regions having a cell shape or another shape and a value of a signal transmitted from an access point (AP) is measured per reference point in each sub-region and is stored in a database. After the received signal is stored in the database, the value of an actually measured signal is compared with the value stored in the database to determine the position of the terminal.
- AP access point
- the fingerprinting method may be largely divided into two steps.
- a region in which the position of the terminal will be measured is divided into sub-regions having a specific shape, the strength of a signal transmitted from the AP to a reference point of each sub-region is measured, and data is collected based on the measured signal strength.
- the actual position of the terminal is estimated using a specific algorithm based on the data stored in the database and the actually measured value of the signal transmitted from the AP.
- FIG. 3( a ) illustrates a signal collection step for position estimation in which the terminal measures the values of the signals received from a plurality of APs (AP1, AP2, AP3 and AP4) at a specific reference point 310 and stores the values in the database.
- FIG. 3( b ) shows a process of estimating the current position of the terminal by applying the strength of the signal from the AP measured at a measurement point 320 and the signal strength stored in the database to the algorithm.
- the Wi-Fi positioning system using fingerprinting does not require time synchronization for position estimation and accurately performs position estimation indoors because multipath components according to environments are included in the database. However, in the Wi-Fi positioning system using fingerprinting, the database of a service region should be established and the database needs to be updated according to internal environment change (AP movement, etc.). Next, as another positioning method, an inertial positioning method will be described in brief.
- Dual band is the capability to transmit on the 5 GHz band of 802.11a and also the 2.4 GHz band used by 802.11b, 802.11g, and 802.11n. Unlike ordinary Wi-Fi equipment that only supports one signal band, dual-band gear contains two different types of wireless radios that can support connections on both 2.4 GHz and 5 GHz links. Dual-band Wi-Fi is a feature of some wireless routers and network adapters.
- dual-band routers Unlike ordinary routers that only support one wireless signal band, dual-band routers contain two different types of wireless radios. When first introduced many years ago, dual-band routers supported both 802.11a and 802.11b and were designed for business networks that used a mix of both types of Wi-Fi clients.
- Some newer 802.11n Wi-Fi routers also allow simultaneous dual band communication with both 2.4 GHz and 5 GHz clients. By supplying separate network bandwidth for each of the two types of links, these routers provide maximum flexibility in setting up a home network. For example, older 802.11b/g clients can be set to run on the 2.4 GHz side of a simultaneous dual-band router without impacting the performance of 802.11n clients running at 5 GHz.
- Dual-band WiFi network adapters likewise contain two wireless radios. These adapters can be configured to use either 802.11a via one radio, or the 802.11b/g/n family via the other, but not both. Using a dual-band adapter allows a terminal to connect to either type of Wi-Fi access point.
- FIG. 4 is a diagram showing a beacon frame used in a Wi-Fi system.
- the beacon frame includes a frame control field, a duration ID field, an Addr 1 field, an Addr 2 field, an Addr 3 field, a sequence control field, an Addr 4 field, a frame body field and a FCS field.
- a frame control field a duration ID field
- an Addr 1 field a field that is added to the beacon frame.
- an Addr 2 field a field that is added to the beacon frame.
- an Addr 3 field a sequence control field
- an Addr 4 field a frame body field
- FCS field FCS field
- a terminal should access a Wi-Fi system, in order to perform positioning based on a received signal.
- a process of accessing the Wi-Fi system will be briefly described.
- the terminal performs scanning in order to access the Wi-Fi system and the scanning method includes a passive scan method (beacon frame reception) and an active scan method (probe request/probe response signal exchange). Thereafter, synchronization is performed using a timestamp included in the beacon frame and an authentication process is performed. After authentication, the terminal accesses the Wi-Fi system through an association process (request/response frame exchange).
- a terminal in a dual-band wireless system may receive a signal from an AP in each band and estimate an indoor position thereof.
- the present invention proposes a method of performing indoor positioning at a terminal using a dual-band wireless system.
- Positioning Method 1 Positioning Method Using Different Band Information
- an AP transmits a beacon frame to a terminal via a channel of each band or transmits/receives a probe request/probe response frame to/from the terminal through the channel of the band, for terminal connection. Accordingly, the terminal having dual band capacity performs scanning with respect to dual band, for connection to the AP.
- a dual-band e.g., 2.4 GHz or 5 GH
- the terminal may receive a beacon frame which is periodically transmitted via each channel of dual band or transmit a probe request frame via each channel of dual band and receive a probe response from the AP, during scanning.
- the terminal may confirm channel information of each band and received signal strength through scanning. Accordingly, the terminal having dual band capacity may increase indoor positioning accuracy by performing positioning using the channel information of dual band confirmed through scanning.
- a positioning method using information about dual band will be described in detail.
- FIG. 5 is a diagram illustrating an indoor positioning method according to Embodiment 1 of the present invention.
- a terminal which performs indoor positioning receives a signal (e.g., a beacon frame, a probe response, data, etc.) from an AP through a channel of an access band (e.g., band 1) (S 510 ).
- a signal e.g., a beacon frame, a probe response, data, etc.
- S 510 Received signal strength (RSS) of the signal from band 1 is measured and stored in a memory 160 (S 520 ).
- Information stored in the memory 160 is at least one of a service set identifier (SSID), a received signal strength indicator (RSSI), a band indicator and a channel indicator.
- SSID service set identifier
- RSSI received signal strength indicator
- the terminal which has stored the above information in the memory 160 may perform band switching in order to measure an RSS of a signal from another band (e.g., band 2) (S 530 ).
- band switching is performed in an inter frame space (IFS) (e.g., a Distributed IFS (DIFS), a PCF IFS (PIFS), a short IFS (SIFS), and an extended IFS (EIFS)) and only the SIFS may be used for fast positioning.
- IFS inter frame space
- DIFS Distributed IFS
- PIFS PCF IFS
- SIFS short IFS
- EIFS extended IFS
- the terminal which moves to another band (e.g., band 2) through band switching within the IFS may perform scanning in order to measure the signal strength of the signal from the band to which the terminal moves (S 540 ).
- the terminal receives a beacon frame from the AP or transmits/receives a probe request frame/probe response frame to/from the AP through scanning or measures an RSS and ToA of the channel of each band through data reception (S 550 and S 560 ).
- the terminal can measure the signal without performing the process of accessing the AP. Therefore, it is possible to reduce latency due to measurement.
- the terminal accesses the AP through a contention based access process and then measures the RSS in order to measure data transmitted by the AP, an accurate RSS can be measured and latency increases.
- the terminal stores the RSS information (e.g., RSSI) and ToA measured using such methods in the memory 160 .
- the terminal which has finished measurement of another band (e.g., band 2) performs band switching during the IFS interval and moves to the initially accessed band (e.g., band 1) (S 570 ).
- the terminal which has performed band switching accesses the AP through the contention based access process in order to transmit, to the AP, information (including an SSID, an RSSI, a band indicator and a channel indicator) about dual band (e.g., band 1 and band 2) confirmed by measurement.
- information including an SSID, an RSSI, a band indicator and a channel indicator
- the terminal which has performed band switching using the SIFS confirms a channel status in the band through the DIFS, applies a back-off time to an idle channel, and accesses the AP through the contention based access process.
- priority is given to a terminal which re-accesses the AP for positioning so as to apply a small back-off time.
- the terminal may not perform a process of re-accessing the AP after band switching if there is a transmission opportunity (TXOP) and may perform measurement without re-access process.
- TXOP transmission opportunity
- the terminal which has re-accessed the AP transmits dual band information stored in the memory 160 to the AP through the data frame.
- the measured dual band information may be transmitted using a control frame or a position request frame instead of the data frame.
- the AP which has received the measured dual band information from the terminal may transmit the information to the location server through a backbone network, a wired network or the Internet or directly obtain the position of the terminal using the information. The positioning method using the dual band information will now be described.
- the terminal In positioning using correction of a distance between an AP and a terminal, the terminal obtains distances between the AP and the terminal through measurement with respect to dual band and performs distance correction using the obtained values to obtain a final position.
- the terminal may measure the RSSI of the signal received from the AP and calculate the distance between the AP and the terminal using the measured value. For example, the distance d between two points may be obtained using Friis's formula as follows.
- the terminal may calculate the distance between the AP and the terminal per band using the RSSI received through each band of the same AP and obtain a final distance between the AP and the terminal through a function (f(d 1 ⁇ d 2 )) using the distance between the AP and the terminal calculated per band.
- a function (f(d 1 ⁇ d 2 )) using the distance between the AP and the terminal calculated per band.
- the method of calculating the distance between the AP and the terminal is only exemplary and (f(d 1 ⁇ d 2 ) for obtaining the distance may be differently defined.
- the position of the terminal may be obtained using a triangulation method as shown in Equation 2.
- ⁇ tilde over ( D 1 2 ) ⁇ ( x ⁇ x 1 ) 2 +( y ⁇ y 1 ) 2
- ⁇ tilde over ( D 2 2 ) ⁇ ( x ⁇ x 2 ) 2 +( y ⁇ y 2 ) 2
- ⁇ tilde over ( D 3 2 ) ⁇ ( x ⁇ x 3 ) 2 +( y ⁇ y 3 ) 2 Equation 2
- ⁇ tilde over (D) ⁇ tilde over (D 1 2 ) ⁇ , ⁇ tilde over (D) ⁇ tilde over (D 2 2 ) ⁇ and ⁇ tilde over (D) ⁇ tilde over (D 3 2 ) ⁇ respectively denote distances between AP1, AP2 and AP3 and a terminal and (x, y) corresponds to a final position of the terminal.
- the distance between the AP and the terminal is calculated per band using the RSSI measured through dual band as shown in Equation 1.
- the calculated distance may be applied to a triangulation method to obtain the position information of the terminal of each band.
- the position information of the terminal measured through the above process per band may be applied to a function (f( ⁇ )) to obtain a final position of the terminal.
- (f( ⁇ )) may be expressed by a function using a mean value of the two pieces of position information and may be expressed by Equation 3 below.
- band 2 e.g., 5 GHz
- band 1 e.g., 2.4 GHz
- a probability that a signal is transmitted and received in a line of sight (LOS) environment is high. Accordingly, since peripheral influence is reduced as compared with a non line of sight (NLOS) environment, it is possible to provide more accurate positioning information.
- the set weighting factor may be used for (1) the positioning method using correction of the distance between the AP and the terminal and (2) the positioning method using calibration correction.
- a high frequency band undergoes much more peripheral interference and influence than a low frequency band. Accordingly, the quality of the signal received via a high frequency band may be low. In this case, if a high weighting factor is applied to the signal received via a high frequency band, error may increase. Accordingly, if the terminal performs measurement with respect to several bands, priority is given to a high frequency band. A determination as to whether a value measured at this time satisfies a predefined threshold is made to perform positioning using only the satisfied value. In addition, the per-band weighting factor may be determined based on the value measured per band.
- a weight may be further applied to the weighting factor for the low frequency band to be used for positioning. That is, at least one of the strength of the signal received per band and a delay time is compared with a predetermined threshold (or threshold condition) to determine whether the received signal length is large or the delay time is short and a relatively large weight factor value may be applied to the distance measured from the band satisfying the threshold.
- a predetermined threshold or threshold condition
- the weighting factor applied per band may be adaptively set by confirming tendencies that the RSS measured by the UE varies during a predetermined period. At this time, the weighting factor may be set by the terminal which measures the RSS or by the AP, the location server or the router based on the RSS information transmitted by the terminal. If the terminal sets the weighting factor, the weighting factor may be immediately used for positioning or transmitted to the AP, the location server or the router to be used at a higher node.
- the location server or the AP receives the information (e.g., SSID, RSSI, band index and channel index) measured by the terminal through dual band as in the positioning method using the RSSI and uses a function f(band 1, band 2, DB 1, DB 2) in order to calculate the position of the terminal using the received information and the positioning information (SSID, RSSI, band indicator and channel indicator) stored in the database.
- band 1 and band 2 indicate positioning information (SSID, RSSI, band indicator and channel indicator) confirmed through measurement in each band and DB1 and DB 2 denote per-position positioning information (including SSID, RSSI, band indicator and channel indicator) according to the band, which is pre-stored in order to check the position of the terminal.
- calculation of the position of the terminal using the function f(band 1, band 2, DB 1, DB 2) may be expressed as shown in Equation 4.
- x b1 denotes a coordinate calculated using an x coordinate position confirmed through signal measurement from band 1 and an x coordinate position stored in the database of band 1
- x b2 denotes a coordinate calculated using an x coordinate position confirmed through signal measurement from band 2 and an x coordinate position stored in the database of band 2.
- y b1 denotes a coordinate calculated using a y coordinate position confirmed through signal measurement from band 1 and a y coordinate position stored in the database of band 1
- y b2 denotes a coordinate calculated using an x coordinate position confirmed through signal measurement from band 2 and a y coordinate position stored in the database of band 2.
- the final position (x, y) of the terminal obtained using the positioning method using fingerprinting may be expressed by
- the position information of the terminal obtained through the above-described method may be calculated by the location server and transmitted to the AP or may be directly calculated by the AP.
- the position information of the terminal calculated by the location server or the AP is transmitted to the terminal through the AP.
- the terminal which has received calibrate information of the position from the AP may confirm the position of the terminal through the above-described information.
- Embodiment 1 the method of, at the terminal, measuring the distance between the terminal and the AP using the received signal strength (RSS) of the signal received from the dual band of the AP was described.
- Embodiment 2 via which channel of the band the terminal receives a signal to perform positioning is described.
- the terminal switches the access band to another band, receives a beacon frame from the AP or transmits a probe request frame to the AP and receives a probe response frame, and measures positioning information.
- the terminal may transmit channel information of the band to be measured and channel use timing information to the AP.
- the channel information of the band to be measured and channel use timing information may be transmitted to the terminal using the following method.
- the terminal transmits the position request frame to the AP
- the AP transmits the position response frame in response to the request and transmits the band to be measured through the frame, the channel information and the channel use timing information.
- the terminal may perform the same positioning method as Embodiment 1 using the band to be measured, the channel information and the channel use timing information received from the AP.
- the AP transmits measurement information of another band to the terminal.
- the information may be transmitted via a data frame.
- the channel of another band for measurement may be predetermined by the terminal according to an access channel or may be flexibly determined by the AP in consideration of the situation of another band when positioning starts and be transmitted to the terminal.
- the terminal which has received the measurement information through the above-described method moves to another band through band switching using the same method as Embodiment 1 and performs measurement using the received information.
- the terminal which has finished measurement of the accessed band and another band, transmits the information to the AP and acquires the position information of the terminal using the methods shown in Embodiment 1.
- the terminal In order to perform positioning using dual band, the terminal disconnects the accessed band, performs band switching, and performs measurement. Next, the terminal moves to the original band and performs a re-access process. At this time, since the Wi-Fi system is a contention based system, the terminal accesses the AP through contention. Since the terminal re-accesses the AP through contention, the terminal experiences high latency in a position measurement process. In order to reduce such latency, the terminal, which performs position estimation, performs communication with the AP using a point coordination function (PCF) without using an existing distributed coordination function (DCF).
- PCF point coordination function
- DCF distributed coordination function
- the terminal transmits the position request frame to the AP to indicate that positioning is performed.
- the AP creates a polling list using the information (SSID, position indication, etc.) confirmed through the received request frame.
- the polling list information is similar to scheduling information indicating when the terminal performs transmission/reception in which band.
- the AP which has created the polling list broadcasts an AP polling list to terminals located in a base station system (BSS).
- the polling list may be created per band or one polling list may include dual band.
- the terminal may perform measurement and feedback operation during a contention free period (CFP) of a superframe included in the polling list and perform band switching using a point inter frame space (PIFS) in a CFP. Accordingly, the terminal which has received the polling list receives a beacon frame and a traffic indication map (TIM) transmitted in the CFP in an access band, receives a signal from the AP, measures an RSS and transmits measurement result information to the AP.
- CFP contention free period
- the terminal which has performed feedback performs band switching to move to another band, receives a beacon frame and a TIM from the AP during the CFP, measures an RSS, and feeds the information back to the AP using a predetermined period.
- the terminal which has performed measurement and feedback for another band performs band switching using a PIFS in a CP/CFP and rapidly re-accesses the AP without contention.
- the AP which has received the measurement information of each band from the terminal transmits the received information to the location server via the Internet, a wired network or a backbone network.
- the location server may calculate the position of the terminal using the received information or the AP may directly calculate the position of the terminal using the information.
- the location server or the AP may calculate the position of the terminal using the methods described in Embodiment 1 in order to estimate the position of the terminal.
- the terminal performs band switching and performs measurement per band in order to estimate the RSS for dual band.
- a terminal simultaneously performs measurement with respect to dual band.
- FIG. 6 is a diagram illustrating an indoor positioning method according to Embodiment 3 of the present invention.
- the terminal simultaneously accesses two bands (e.g., band 1 and band 2) (S 610 ) and receives signals from the two bands (S 620 ).
- the terminal simultaneously performs measurement with respect to two bands (e.g., band 1 and band 2) using the signals received from the two bands (S 630 ).
- the SSID, RSS information, channel indication and band indication information acquired by measuring the signals from the two bands are transmitted to the AP (S 640 ).
- the information about the two bands may be transmitted using one band and information about each band may be transmitted to the AP through each band.
- the AP which has received the measurement result information from the terminal may transmit the measurement result information to the location server (S 650 ).
- the location server may calculate the position of the terminal using the measurement result information received from the AP and transmits the position of the terminal to the AP.
- the AP may directly calculate the position of the terminal using the measurement result information.
- the method of calculating the position of the terminal at the location server or the AP may be performed according to any one of the above-described embodiments.
- one terminal performs measurement with respect to dual band and performs positioning.
- the terminal may perform positioning through collaboration with a collaborative terminal That is, the terminal which performs positioning performs measurement with respect to one band (e.g., band 1) and receives information about another band (e.g., band 2) from the neighboring collaborative terminal.
- one band e.g., band 1
- another band e.g., band 2
- the terminal may transmit the measurement result information and the information received from the collaborative terminal to the AP, the router or the location server and the AP, the router or the location server may calculate the position of the terminal using the measurement result information.
- the terminal may directly calculate the position thereof using the measurement result information.
- the above-described methods are applicable.
- the indoor positioning methods of the terminal may be performed by the AP, the location server or the router and the position of the terminal may be transmitted to the terminal, as described above.
- the terminal may directly calculate the position thereof using the proposed method and algorithm without the AP, the location server or the router.
- the positioning method proposed by the present invention is applicable to an algorithm for calculating the position of the terminal using a ToA and ToD confirmed through the signal transmitted through dual band to estimate the position of the terminal.
- the same method is applicable to wireless LAN or Wi-Fi using one or more bands.
- the number of bands is not limited to 2 and the present invention is applicable to a system having three or more bands.
- a Wi-Fi system used for positioning in the present invention is only exemplary and a wireless system used in the present invention is not limited to Wi-Fi.
- the position of the terminal can be more accurately estimated indoors using Wi-Fi using one or more bands, it is possible to increase positioning accuracy.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Mobile Radio Communication Systems (AREA)
- Position Fixing By Use Of Radio Waves (AREA)
Abstract
Description
TroundA denotes a time required when a packet is transmitted by a transmitter (Node A) to a receiver (Node B) through an arbitrary number of intermediate connections or communication networks and then a response signal thereto arrives at the transmitter (Node A) through the intermediate connections or communication networks.
{tilde over (D)}=(f(d 1 ·d 2))=D 1 +D 2/2
{tilde over (D 1 2)}=(x−x 1)2+(y−y 1)2
{tilde over (D 2 2)}=(x−x 2)2+(y−y 2)2
{tilde over (D 3 2)}=(x−x 3)2+(y−y 3)2
(f(·))=f(P 1 ·P 2)=f((x 1 ·y 1),(x 2 ·y 2))=(x 1 +x 2/2,y 1 +y 2/2)
Although the final position (x, y) of the terminal is obtained through averaging, this is only exemplary and f(
Claims (17)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/959,380 US8971922B2 (en) | 2012-08-05 | 2013-08-05 | Apparatus and method for measuring position of terminal located in indoor using wireless network |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US201261679769P | 2012-08-05 | 2012-08-05 | |
US13/959,380 US8971922B2 (en) | 2012-08-05 | 2013-08-05 | Apparatus and method for measuring position of terminal located in indoor using wireless network |
Publications (2)
Publication Number | Publication Date |
---|---|
US20140045520A1 US20140045520A1 (en) | 2014-02-13 |
US8971922B2 true US8971922B2 (en) | 2015-03-03 |
Family
ID=50066581
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/959,380 Expired - Fee Related US8971922B2 (en) | 2012-08-05 | 2013-08-05 | Apparatus and method for measuring position of terminal located in indoor using wireless network |
Country Status (1)
Country | Link |
---|---|
US (1) | US8971922B2 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20140064126A1 (en) * | 2012-08-30 | 2014-03-06 | Lg Electronics Inc. | Apparatus and method for calculating location of mobile station in wireless network |
US9668233B1 (en) | 2016-07-12 | 2017-05-30 | Xirrus, Inc. | Wireless communication network with distributed device location determination |
US9924438B1 (en) * | 2015-06-18 | 2018-03-20 | Amazon Technologies, Inc. | Frequency acquisition during roaming |
Families Citing this family (40)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9288623B2 (en) | 2005-12-15 | 2016-03-15 | Invisitrack, Inc. | Multi-path mitigation in rangefinding and tracking objects using reduced attenuation RF technology |
US9913244B2 (en) | 2005-12-15 | 2018-03-06 | Polte Corporation | Partially synchronized multilateration or trilateration method and system for positional finding using RF |
US10281557B2 (en) | 2005-12-15 | 2019-05-07 | Polte Corporation | Partially synchronized multilateration/trilateration method and system for positional finding using RF |
US9699607B2 (en) | 2005-12-15 | 2017-07-04 | Polte Corporation | Multi-path mitigation in rangefinding and tracking objects using reduced attenuation RF technology |
US10091616B2 (en) | 2005-12-15 | 2018-10-02 | Polte Corporation | Angle of arrival (AOA) positioning method and system for positional finding and tracking objects using reduced attenuation RF technology |
US10834531B2 (en) | 2005-12-15 | 2020-11-10 | Polte Corporation | Multi-path mitigation in rangefinding and tracking objects using reduced attenuation RF technology |
US9813867B2 (en) | 2005-12-15 | 2017-11-07 | Polte Corporation | Angle of arrival (AOA) positioning method and system for positional finding and tracking objects using reduced attenuation RF technology |
US11835639B2 (en) | 2011-08-03 | 2023-12-05 | Qualcomm Technologies, Inc. | Partially synchronized multilateration or trilateration method and system for positional finding using RF |
EP3091367B1 (en) | 2011-08-03 | 2019-10-09 | PoLTE Corporation | Multi-path mitigation in rangefinding and tracking objects using reduced attenuation rf technology |
US11125850B2 (en) | 2011-08-03 | 2021-09-21 | Polte Corporation | Systems and methods for determining a timing offset of emitter antennas in a wireless network |
US10845453B2 (en) | 2012-08-03 | 2020-11-24 | Polte Corporation | Network architecture and methods for location services |
US10440512B2 (en) | 2012-08-03 | 2019-10-08 | Polte Corporation | Angle of arrival (AOA) positioning method and system for positional finding and tracking objects using reduced attenuation RF technology |
US10863313B2 (en) | 2014-08-01 | 2020-12-08 | Polte Corporation | Network architecture and methods for location services |
US9002375B1 (en) * | 2013-03-15 | 2015-04-07 | Groupon, Inc. | Presence detection based on crowd surfing signal strength |
US9813980B2 (en) * | 2013-03-22 | 2017-11-07 | Acer Incorporated | Methods for assisting mobile communication devices in connecting to an access point (AP), and mobile communication devices and base stations using the same |
US9554396B2 (en) * | 2013-09-30 | 2017-01-24 | Broadcom Corporation | Multi-interface WLAN device with time arbitration messaging |
US10102755B1 (en) | 2013-10-07 | 2018-10-16 | Satcom Direct, Inc. | Method and system for aircraft positioning—automated tracking using onboard global voice and high-speed data |
US9553658B1 (en) * | 2013-10-09 | 2017-01-24 | Satcom Direct, Inc. | Router for aircraft communications with simultaneous satellite connections |
US9565618B1 (en) | 2013-10-09 | 2017-02-07 | Satcom Direct, Inc. | Air to ground management of multiple communication paths |
US9577742B1 (en) | 2013-10-10 | 2017-02-21 | Satcom Direct, Inc. | Data compression and acceleration for air to ground communications |
US10049508B2 (en) | 2014-02-27 | 2018-08-14 | Satcom Direct, Inc. | Automated flight operations system |
US9220081B2 (en) * | 2014-03-05 | 2015-12-22 | Intel Corporation | Access point location discovery in unmanaged networks |
CN105025569B (en) * | 2014-04-30 | 2018-12-04 | 中国移动通信集团北京有限公司 | A kind of method, system and device of indoor positioning |
US11397258B2 (en) * | 2015-07-17 | 2022-07-26 | Origin Wireless, Inc. | Method, apparatus, and system for outdoor target tracking |
US9554275B1 (en) | 2014-10-19 | 2017-01-24 | Satcom Direct, Inc. | Voice and SMS communication from a mobile device over IP network and satellite or other communication network |
CN104394589A (en) * | 2014-11-20 | 2015-03-04 | 北京东霖消防科技有限公司 | Individual combat location base station |
US10993147B1 (en) | 2015-02-25 | 2021-04-27 | Satcom Direct, Inc. | Out-of-band bandwidth RSVP manager |
CN105334493B (en) * | 2015-10-09 | 2017-12-26 | 北京航空航天大学 | A kind of indoor orientation method based on WLAN |
US11275149B2 (en) * | 2016-03-18 | 2022-03-15 | Embarcadero Technologies, Inc. | Determining a location of an electronic device |
TWI746474B (en) * | 2016-11-03 | 2021-11-21 | 司圖科技股份有限公司 | Device and method of indoor positioning reference data collection and method for indoor positioning |
CN106535133A (en) * | 2016-11-11 | 2017-03-22 | 天津大学 | Indoor telephone traffic accurate location method based on machine learning in cellular network |
FR3060251B1 (en) * | 2016-12-09 | 2019-05-10 | Sagemcom Broadband Sas | METHOD OF PAIRING A WI-FI TYPE TERMINAL AT A WI-FI TYPE ACCESS POINT |
WO2018201670A1 (en) | 2017-05-05 | 2018-11-08 | Qualcomm Incorporated | Ue selection of common and dedicated rach resources |
WO2019078996A1 (en) * | 2017-10-22 | 2019-04-25 | Intel IP Corporation | Apparatus, system and method of collaborative time of arrival (ctoa) measurement |
US11255945B2 (en) | 2018-03-27 | 2022-02-22 | Polte Corporation | Multi-path mitigation in tracking objects using compressed RF data |
TWI659664B (en) * | 2018-07-06 | 2019-05-11 | 神達電腦股份有限公司 | Electronic device positioning method |
WO2020040589A1 (en) * | 2018-08-23 | 2020-02-27 | 엘지전자 주식회사 | Method and device for configuring links for executing communication in wireless lan system |
CN109246798A (en) * | 2018-10-16 | 2019-01-18 | 杭州迪普科技股份有限公司 | The processing method and processing device of terminal access in a kind of WLAN |
CN113325366A (en) * | 2021-05-31 | 2021-08-31 | 湖北微特传感物联研究院有限公司 | Personnel positioning method and system |
CN113645563B (en) * | 2021-07-02 | 2023-08-11 | 北京航天控制仪器研究所 | Communication positioning and Internet of things integrated indoor information network |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020168989A1 (en) * | 2001-03-30 | 2002-11-14 | Koninklijke Philips Electronics N.V. | Method of determining position in a cellular communications network |
US6944096B2 (en) * | 2002-08-21 | 2005-09-13 | Westerngeco, L.L.C. | Method of accurately determining positions of deployed seismic geophones |
US20080032705A1 (en) * | 2006-08-04 | 2008-02-07 | Abhishek Patel | Systems and methods for determining location of devices within a wireless network |
US20120026036A1 (en) * | 2007-03-27 | 2012-02-02 | Eikonik Inc. | Methods and Systems for Location Determination Via Multi-Mode Operation |
US20130045754A1 (en) * | 2005-12-15 | 2013-02-21 | Invisitrack, Inc. | Multi-Path Mitigation in Rangefinding and Tracking Objects Using Reduced Attenuation RF Technology |
-
2013
- 2013-08-05 US US13/959,380 patent/US8971922B2/en not_active Expired - Fee Related
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020168989A1 (en) * | 2001-03-30 | 2002-11-14 | Koninklijke Philips Electronics N.V. | Method of determining position in a cellular communications network |
US6944096B2 (en) * | 2002-08-21 | 2005-09-13 | Westerngeco, L.L.C. | Method of accurately determining positions of deployed seismic geophones |
US20130045754A1 (en) * | 2005-12-15 | 2013-02-21 | Invisitrack, Inc. | Multi-Path Mitigation in Rangefinding and Tracking Objects Using Reduced Attenuation RF Technology |
US20080032705A1 (en) * | 2006-08-04 | 2008-02-07 | Abhishek Patel | Systems and methods for determining location of devices within a wireless network |
US20120026036A1 (en) * | 2007-03-27 | 2012-02-02 | Eikonik Inc. | Methods and Systems for Location Determination Via Multi-Mode Operation |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20140064126A1 (en) * | 2012-08-30 | 2014-03-06 | Lg Electronics Inc. | Apparatus and method for calculating location of mobile station in wireless network |
US9313669B2 (en) * | 2012-08-30 | 2016-04-12 | Lg Electronics Inc. | Apparatus and method for calculating location of mobile station in wireless network |
US9924438B1 (en) * | 2015-06-18 | 2018-03-20 | Amazon Technologies, Inc. | Frequency acquisition during roaming |
US9668233B1 (en) | 2016-07-12 | 2017-05-30 | Xirrus, Inc. | Wireless communication network with distributed device location determination |
US10517060B2 (en) | 2016-07-12 | 2019-12-24 | Cambium Networks, Ltd. | Wireless communication network with distributed device location determination |
Also Published As
Publication number | Publication date |
---|---|
US20140045520A1 (en) | 2014-02-13 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US8971922B2 (en) | Apparatus and method for measuring position of terminal located in indoor using wireless network | |
US10624055B2 (en) | Method for determining location of wireless devices | |
CN104904145B (en) | Method and apparatus, equipment and the management system estimated for RF performance metrics | |
US20200267684A1 (en) | RSRP Reporting Methods for NR High Resolution Angle-based Downlink Positioning | |
US20210328747A1 (en) | Measurement method and device | |
US7349441B2 (en) | Method for optimizing communication within a wireless network | |
CN113785633B (en) | Method for locating a wireless communication device, method for facilitating locating | |
US20150219750A1 (en) | Positioning method and apparatus | |
US9288625B2 (en) | Method for determining location of wireless devices based on information within messages received from other network devices | |
US20120302254A1 (en) | Apparatus and method for determining a location of wireless communication devices | |
US20150382152A1 (en) | Method for determining location of wireless devices | |
CN112333624A (en) | Method and communication device for positioning | |
US20140274160A1 (en) | Method and apparatus for positioning user equipment | |
US20140269400A1 (en) | Broadcasting short interframe space information for location purposes | |
EP2763478B1 (en) | Method and device using observed time difference of arrival for positioning mobile station | |
US9629117B2 (en) | Method, apparatus, and computer program product for location determination using WiFi | |
CN104871616A (en) | Methods of positioning in a system comprising measuring nodes with multiple receiving points | |
CN107734454A (en) | The device of location of user equipment is determined using the signal from WLAN | |
CN104662436B (en) | Localization method and device | |
WO2016081271A1 (en) | Passive locationing over multiple channels | |
US9820256B2 (en) | Apparatus, system and method of time-of-flight positioning via neighbor list | |
US20120249300A1 (en) | Determination of location using rssi and transmit power | |
CN112369086A (en) | Method, apparatus, and computer-readable medium for beam information based positioning | |
CN113810991A (en) | Positioning method and device | |
US10182413B2 (en) | Wireless positioning using scheduled transmissions |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: LG ELECTRONICS INC., KOREA, REPUBLIC OF Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:LIM, DONGGUK;KIM, DONGCHEOL;KANG, JINWON;AND OTHERS;SIGNING DATES FROM 20130812 TO 20130813;REEL/FRAME:031064/0843 |
|
AS | Assignment |
Owner name: LG ELECTRONICS INC., KOREA, REPUBLIC OF Free format text: CORRECTIVE ASSIGNMENT TO CORRECT THE SPELLING OF THE 3RD INVENTOR'S NAME FROM JINWON KANG TO JIWON KANG PREVIOUSLY RECORDED ON REEL 031064 FRAME 0843. ASSIGNOR(S) HEREBY CONFIRMS THE CORRECT INVENTOR'S NAME IS JIWON KANG;ASSIGNORS:LIM, DONGGUK;KIM, DONGCHEOL;KANG, JIWON;AND OTHERS;SIGNING DATES FROM 20130812 TO 20130813;REEL/FRAME:031589/0366 |
|
FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
FEPP | Fee payment procedure |
Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
LAPS | Lapse for failure to pay maintenance fees |
Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20190303 |